Introduction to Java Programming, AP Version,
Y. Daniel Liang
This quiz is for students to practice. A large number of additional quiz is available for instructors from the Instructor's Resource Website.
Chapter 6 Methods
Sections 6.2 Defining a Method
6.1
Suppose your method does not return any value, which of the following keywords can be used as a return type?
A.
void
B.
int
C.
double
D.
public
E.
None of the above
6.2
The signature of a method consists of ____________.
A.
method name
B.
method name and parameter list
C.
return type, method name, and parameter list
D.
parameter list
6.3
All Java applications must have a method __________.
A.
public static Main(String[] args)
B.
public static Main(String args[])
C.
public static void main(String[] args)
D.
public void main(String[] args)
E.
public static main(String[] args)
Sections 6.3 Calling a Method
6.4
Arguments to methods always appear within __________.
A.
brackets
B.
parentheses
C.
curly braces
D.
quotation marks
6.5
Does the return statement in the following method cause compile errors?
public
static
void
main(String[] args) {
int
max =
0
;
if
(max !=
0
)
System.out.println(max);
else
return
;
}
A.
Yes
B.
No
6.6
Does the method call in the following method cause compile errors?
public
static
void
main(String[] args) {
Math.pow(
2
,
4
);
}
A.
Yes
B.
No
6.7
Each time a method is invoked, the system stores parameters and local variables in an area of memory, known as _______, which stores elements in last-in first-out fashion.
A.
a heap
B.
storage area
C.
a stack
D.
an array
Sections 6.4 void Method Example
6.8
Which of the following should be defined as a void method?
A.
Write a method that prints integers from 1 to 100.
B.
Write a method that returns a random integer from 1 to 100.
C.
Write a method that checks whether current second is an integer from 1 to 100.
D.
Write a method that converts an uppercase letter to lowercase.
6.9
You should fill in the blank in the following code with ______________.
public
class
Test {
public
static
void
main(String[] args) {
System.out.print(
"The grade is "
);
printGrade(
78
.
5
);
System.out.print(
"The grade is "
);
printGrade(
59
.
5
);
}
public
static
__________ printGrade(
double
score) {
if
(score >=
90
.
0
) {
System.out.println(
'A'
);
}
else
if
(score >=
80
.
0
) {
System.out.println(
'B'
);
}
else
if
(score >=
70
.
0
) {
System.out.println(
'C'
);
}
else
if
(score >=
60
.
0
) {
System.out.println(
'D'
);
}
else
{
System.out.println(
'F'
);
}
}
}
A.
int
B.
double
C.
boolean
D.
char
E.
void
6.10
You should fill in the blank in the following code with ______________.
public
class
Test {
public
static
void
main(String[] args) {
System.out.print(
"The grade is "
+ getGrade(
78
.
5
));
System.out.print(
"\nThe grade is "
+ getGrade(
59
.
5
));
}
public
static
_________ getGrade(
double
score) {
if
(score >=
90
.
0
)
return
'A'
;
else
if
(score >=
80
.
0
)
return
'B'
;
else
if
(score >=
70
.
0
)
return
'C'
;
else
if
(score >=
60
.
0
)
return
'D'
;
else
return
'F'
;
}
}
A.
int
B.
double
C.
boolean
D.
char
E.
void
Sections 6.5 Passing Parameters by Values
6.11
When you invoke a method with a parameter, the value of the argument is passed to the parameter. This is referred to as _________.
A.
method invocation
B.
pass by value
C.
pass by reference
D.
pass by name
6.12
Given the following method
static
void
nPrint(String message,
int
n) {
while
(n >
0
) {
System.out.print(message);
n--;
}
}
What is the output of the call nPrint(
'a'
,
4
)?
A.
aaaaa
B.
aaaa
C.
aaa
D.
invalid call
6.13
Given the following method
static
void
nPrint(String message,
int
n) {
while
(n >
0
) {
System.out.print(message);
n--;
}
}
What is k after invoking nPrint(
"A message"
, k)?
int
k =
2
;
nPrint(
"A message"
, k);
A.
0
B.
1
C.
2
D.
3
Section 6.8 Overloading Methods
6.14
Analyze the following code:
public
class
Test {
public
static
void
main(String[] args) {
System.out.println(xMethod(
5
,
500L
));
}
public
static
int
xMethod(
int
n,
long
l) {
System.out.println(
"int, long"
);
return
n;
}
public
static
long
xMethod(
long
n,
long
l) {
System.out.println(
"long, long"
);
return
n;
}
}
A.
The program displays int, long followed by 5.
B.
The program displays long, long followed by 5.
C.
The program runs fine but displays things other than 5.
D.
The program does not compile because the compiler cannot distinguish which xmethod to invoke.
6.15
Analyze the following code:
class
Test {
public
static
void
main(String[] args) {
System.out.println(xmethod(
5
));
}
public
static
int
xmethod(
int
n,
long
t) {
System.out.println(
"int"
);
return
n;
}
public
static
long
xmethod(
long
n) {
System.out.println(
"long"
);
return
n;
}
}
A.
The program displays int followed by 5.
B.
The program displays long followed by 5.
C.
The program runs fine but displays things other than 5.
D.
The program does not compile because the compiler cannot distinguish which xmethod to invoke.
6.16
Analyze the following code.
public
class
Test {
public
static
void
main(String[] args) {
System.out.println(max(
1
,
2
));
}
public
static
double
max(
int
num1,
double
num2) {
System.out.println(
"max(int, double) is invoked"
);
if
(num1 > num2)
return
num1;
else
return
num2;
}
public
static
double
max(
double
num1,
int
num2) {
System.out.println(
"max(double, int) is invoked"
);
if
(num1 > num2)
return
num1;
else
return
num2;
}
}
A.
The program cannot compile because you cannot have the print statement in a non-void method.
B.
The program cannot compile because the compiler cannot determine which max method should be invoked.
C.
The program runs and prints 2 followed by "max(int, double)" is invoked.
D.
The program runs and prints 2 followed by "max(double, int)" is invoked.
E.
The program runs and prints "max(int, double) is invoked" followed by 2.
6.17
Analyze the following code.
public
class
Test {
public
static
void
main(String[] args) {
System.out.println(m(
2
));
}
public
static
int
m(
int
num) {
return
num;
}
public
static
void
m(
int
num) {
System.out.println(num);
}
}
A.
The program has a compile error because the two methods m have the same signature.
B.
The program has a compile error because the second m method is defined, but not invoked in the main method.
C.
The program runs and prints 2 once.
D.
The program runs and prints 2 twice.
Section 6.9 The Scope of Variables
6.18
A variable defined inside a method is referred to as __________.
A.
a global variable
B.
a method variable
C.
a block variable
D.
a local variable
6.19
What is k after the following block executes?
{
int
k =
2
;
nPrint(
"A message"
, k);
}
System.out.println(k);
A.
0
B.
1
C.
2
D.
k is not defined outside the block. So, the program has a compile error
Section 6.10 Case Study: Generating Random Characters
6.20
(int)(Math.random() * (65535 + 1)) returns a random number __________.
A.
between 1 and 65536
B.
between 1 and 65535
C.
between 0 and 65535
D.
between 0 and 65536
6.21
(int)('a' + Math.random() * ('z' - 'a' + 1)) returns a random number __________.
A.
between 0 and (int)'z'
B.
between (int)'a' and (int)'z'
C.
between 'a' and 'z'
D.
between 'a' and 'y'
6.22
(char)('a' + Math.random() * ('z' - 'a' + 1)) returns a random character __________.
A.
between 'a' and 'z'
B.
between 'a' and 'y'
C.
between 'b' and 'z'
D.
between 'b' and 'y'
6.23
Which of the following is the best for generating random integer 0 or 1?
A.
(int)Math.random()
B.
(int)Math.random() + 1
C.
(int)(Math.random() + 0.5)
D.
(int)(Math.random() + 0.2)
E.
(int)(Math.random() + 0.8)
Section 6.11 Method Abstraction and Stepwise Refinement
6.24
The client can use a method without knowing how it is implemented. The details of the implementation are encapsulated in the method and hidden from the client who invokes the method. This is known as __________.
A.
information hiding
B.
encapsulation
C.
method hiding
D.
simplifying method
6.25
__________ is to implement one method in the structure chart at a time from the top to the bottom.
A.
Bottom-up approach
B.
Top-down approach
C.
Bottom-up and top-down approach
D.
Stepwise refinement
6.26
__________ is a simple but incomplete version of a method.
A.
A stub
B.
A main method
C.
A non-main method
D.
A method developed using top-down approach
Section: Extra Questions
6.27
Consider the following incomplete code:
public
class
Test {
public
static
void
main(String[] args) {
System.out.println(f(
5
));
}
public
static
int
f(
int
number) {
// Missing body
}
}
The missing method body should be ________.
A.
return "number";
B.
System.out.println(number);
C.
System.out.println("number");
D.
return number;